Hi all - looking to do some work on the 31 roadster this winter and I had a couple of questions. My frame is unboxed and I found a crack in it so Boxing and sorting out that is 100% for sure. I'm running a SBC350/TH350 combo with a 57 chev rear axle. I notice that the speedway frame and others don't have a K or X framing - whats the general belief there? Was the 32 frame K'd because they didn't box it? Or does the 350/350 provide a certain amount of rigidity with the trans mount that no k or x is required? I have a channeled body, buggy rear, split bones with a spring and solid dropped axle in front.
A lot of aftermarket "A" frames just have a center cross member.. I buy mine from "Brookville Roadster" because I used to work there and theirs only has a center cross member.. Never had a problem and I have used 6 of them...
It's a fair question because A frames are routinely sold with just a single cross member. They will be built to run exactly the same driveline as a deuce, yet the deuce frames (sold by the same people) have cross member tubes in X and K shapes all over the place. Dagels seem to have nice tradish looking X member for A bones.
Great info guys - I'd be curious to hear if others have had issues just using the standard center cross member. The engine is pretty stock - 4 barrel 1406, she's a cruiser and we don't really intend on getting on it but every now and then it's nice to know you canz
I tend to "overbuild" my stuff, although I've learned to appreciate and learn that steel and wood are stronger than I realize. That said, I bought some 4" wide 11 ga. plate to box my A frame and then added the Dagles X-member. Y-block with a cam, t-5 and 3.55 Ford 8" posi. Will probably only be a driver at my age, but I get a certain comfort level from what I've done. Plus I might light'em up now and then.
Model A frames tend to "sag" near where the original rear motor mounts were attached. Sometimes they will crack between the holes. This is just ahead of the middle crossmember. I have seen as much as a 1/2" "dip". Make sure you straighten your ch***is before welding the boxing plates. The center crossmember is ok, but an "X" member is stronger.
I bought a tublar "K" member kit from So Cal speed shop & their ladder bar kit. It leaves you a lot more room for everything that gets cramed under there. You might want to check that out as an option before you buy or make anything. Bill
A frames work fine ( especially if you already have one). Box it and make your own "K" member or whatever you want to call it. I've built a bunch of A's on these frames, have put in V-8's and 4 speeds, and never had a problem. Look at some of the Model A build threads on here and see what other people have done, either utilizing the stock crossmember ( modified), or making their own. A new "perimeter" frame is going to set you back 1 to 2 grand, and a "K" member another 500 bucks- do it yourself and spend the money on stuff you can't make ( beer and pizza!). Good luck with it.
With just a center cross member and boxed the frame will be a little wiggly. Not so much that you would notice. The engine and trans won't ad much rigidity to the frame unless it is solid mounted. One thing you will notice with the A frame is that it is not as deep as the B ch***is. it would be a little difficult to build the structure in it that you see in a Deuce frame because of that. Some guys build torque stays into them that go from the rear cross member near the frame rails to the center of the transmission cross member and that stiffens them up some. A properly built roll bar or cage will stiffen one up as well.
The crack is roughly 4" in front of the ****** crossmember. Looks like it may have been repaired once and the weld gave out. It goes along the bottom of the C and makes the bend north probably about a third of the way up. Appears that someone may have drilled thru to stop the crack as I see what appears to be a bit of filler at the top of the crack. I've got a local reputable hot rodder that I'm going to run it over and have him work some temporary magic on it until I can start a tear down. I never liked the condition of the frame and body - I think the frame isn't square and the body doesn't have a subframe so it's not super rigid.
When you box the frame, consider making a K member out of 4 x 2 x 1/8th tubing, in place of the stock A center cross member. Model it in a 2 x 4 wood and have a good look at the fit-function.
The center cross member ( if that's what you're talking about) isn't a ****** mount. In a stock Model A with a 4 banger, the ****** is held up by the bell housing- the motor has three mounts, one behind the crank pulley that attaches to the front cross member, and one on each side toward the back of the block casting ( right in front of the bellhousing. The 3 speed ****** is pretty small ( and light) and it doesn't require a lot to hold it up. You should post PICTURES- always helps, and keeps people from YELLING at you in capital letters to do so.
I can post some pics. My question was more about the differences I'm seeing in basically the same frame with the same engine/trans and less about my crack
Heres a view looking at the rear of the ******. You can see how theres a tubular brace between the rails that supports the back of the th350. Where that tube meets the frame, they boxed the frame about 4"... Then moving toward the front there's open frame again, then there's boxing for another 4" on both sides. Since someone suggested frame sag there is common perhaps thats why someone put it a bit of boxing, but they should have done the whole length.
4" of boxing is a waste of time, and that ****** mount looks a bit su****ious also. And that cross member isn't doing much; the structural integrity has been compromised by cutting the sides off the "C" shape- now it's a 30" piece of 3/16 flat stock. (Sorry, but that's what I'm seeing.) That crack is pretty bad; from the pictures it looks like it almost failed totally. If you're going to keep that frame, I'd at least fit a piece of "C" cannel ( maybe 24")centered on the break inside the frame rail before boxing (once you take the bow (?) out of the frame). Before you weld the inside , drill some 3/8 holes on the outside rail every few inches along the top and bottom of the face so you can "plug" weld too. Depending on how much you're planning on doing to the car, I'd give serious consideration to a better frame, even a stock one. And personally, I've never seen one of these frames "sag"-- twist, yes. The were designed to flex, that's why they're riveted and not welded. "Flexible Flyers". A lot of them rust right there under the splash aprons. May just be a case of a tired 85 year old frame. Good thing is, it can all be fixed! Good luck with it.
That crack is where it is becouse of the weld at that crossmember. I would think boxing the frame and tieing that boxing plate into the crossmember will fix you up.
Yeah, I hear you on that ****** mount - I think that someone put it in and either there was a different trans or something else was going on because if it was raised that tube the additional support wouldn't need to be there. I think that notched bit above is adding some support to the floorboard. I've never liked the frame or subframe of the body from the day we bought the car. I'm looking forward to a teardown and sorting it all out and knowing that it was put together right. I think if I box it and use that Dagel cross-member it will be pretty solid for my needs but until I get the body off it's hard to know - it might be better to start with a clear frame. All I know is I need to get this projected sorted for my wife so I can start on my project ;-)
Mike Bowling knows what he's talking about. I think he is building his sixth model a, all on A frames, within a ten year period. His cars drive straight and true. Look for "skoog special" by onekoolkat50 and "midnite special" by pete on here. They used the factory ctr member and modified it. Looks to me like most anyone with decent welding/fab skills could get you fixed up in a jiffy. Good luck, Ron
Wow, if you are going to work on your car this winter you may want to consider removing the body and do everything right. That crack is serious and I would get someone that can weld proficiently to do the repair and the boxing. You may want to back it up with a piece of flat plate and plug weld it. That crack is not typical of some I have seen on Model As and I have been playing with them since 1968. Just be glad you found it and it didn't fail while you were driving the car.
I bought a Brookville frame for my 29 roadster project. Nice frame, but the body fit perfectly on the original frame. I am having to do some work to move the body mounting holes in the frame etc. I wish I would have kept the stock frame!
I would also pull body and do it right if it were my car. That section has been hacked out so there is no torsional rigidity so it would be twisting all the time. Fatigue did the rest and failure is next. Box the entire ch***is and add a centre K member. Do it once, do it right. You might find some other engineering marvels in the process. Looking at photos engine / trans could be slightly lower so the centre section can be repaired to add strength. Either that or cut it out and replace with a decent K member with drop down transmission support. As a matter of course that's the standard down here. A solid foundation is a basic necessity.
Thanks guys. I've got it at the shop now getting a temp patch - this guy is an old school hot rodder and he's done plenty of frame work including building his own so I trust his opinion and work. Yes, the body will be pulled when we do this - I'd hate to show you pics of the way the body is hacked up after the frame comments! Ha!
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